A.截面的慣性矩 B.截面系數(shù) C.截面系數(shù)與截面積的比值
A.1400MPa B.1550MPa C.1650MPa D.1750IVIPa
A.縱向游擺 B.斜向游擺 C.橫向游擺
A.10 B.15 C.20~25